<?php
/*
 * suMinify.php
 * 压缩并合并多个js或css文件为一个.min文件
 * 有了这个就不用每次都上网去在线压缩了,而且可以多个文件合并一个,更高级更好用~
 * 开发周期：2015-6-2 16:22到2015-6-22 18:12, 共1小时50分搞定.
 * @since 1.0 <2015-6-2> SoChishun <14507247@qq.com> Added.
 * @since 1.2 <2015-6-5> SoChishun 
 *      1.增加统计功能,压缩效率一目了然;
 *      2.优化脚本逻辑,降低内存占用,极大提升处理效率;
 * @since 1.3 <2015-6-6> SoChishun 新增内容替换功能
 * @since 1.4 <2015-6-8> SoChishun 新增忽略压缩功能
 * @since 1.5 <2015-6-15> SoChishun 
 *      1.新增配置文件外置功能 ('soui_v3a' => 'F:\PDC\ProjectEnv\xcall150505\Public\Theme\XCall\Soui3.0a\config.php')
 *      2.新增就地压缩功能(支持内容替换) ('in-place-minify'=>array('F:\PDC\ProjectEnv\xcall150505\Public\Jquery\jquery-easyui-1.4.2\locale\easyui-lang-zh_CN.js'))
 *      3.新增对目录中所有文件批量压缩功能(支持内容替换和部分忽略) (array('path'=>'F:\PDC\ProjectEnv\xcall150505\Public\Theme\XCall\Soui3.0b\Script\*','replaces' => array("'icons/" => "'../Icons/"),'skips'=>array()))
 */
$ver = '1.5';
/**
 * 配置文件
 * 要先在这里把文件路径配置好!
 * @since 1.0 <2015-6-2> SoChishun Added.
 * @example
 *   'F:\PDC\ProjectEnv\xcall150505\Public\Theme\XCall\Soui3.0b\CssMin\jq-frameset.min.css' => array(
 *      array('path' => 'F:\PDC\ProjectEnv\xcall150505\Public\Css\cssreset-min.css', 'minify' => false), // 不压缩
 *      array('path' => 'F:\PDC\ProjectEnv\xcall150505\Public\Jquery\jquery-easyui-1.4.2\themes\default\easyui.css', 'minify' => false), // 不压缩
 *      array('path' => 'F:\PDC\ProjectEnv\xcall150505\Public\Jquery\jquery-easyui-1.4.2\themes\icon.css', 'replaces' => array("'icons/" => "'../Icons/")), // 内容替换
 *      'F:\PDC\ProjectEnv\xcall150505\Public\Theme\XCall\Soui3.0b\Css\frm-layout.css', // 压缩
 *      'F:\PDC\ProjectEnv\xcall150505\Public\Theme\XCall\Soui3.0b\Css\*', // 整个目录压缩
 *      array('F:\PDC\ProjectEnv\xcall150505\Public\Theme\XCall\Soui3.0b\Css\*','skips'=>array()), // 整个目录压缩,忽略其中部分文件
 *   )
 */
$config = array(
// soui_v3a项目,soui2.0的CDN资源优化版本
    'soui_v3a' => 'F:\PDC\ProjectEnv\xcall150505\Public\Theme\XCall\Soui3.0a\config.php',
    // soui_v3b项目,全新jeasyui框架改进版
    'soui_v3b' => array(
        'js' => array(
            'in-place-minify' => array(// 就地压缩js
                'F:\PDC\ProjectEnv\xcall150505\Public\Jquery\jquery-easyui-1.4.2\locale\easyui-lang-zh_CN.js',
                array('path' => 'F:\PDC\ProjectEnv\xcall150505\Public\Theme\XCall\Soui3.0b\Script\*', 'skips' => array('F:\PDC\ProjectEnv\xcall150505\Public\Theme\XCall\Soui3.0b\Script\frm-layout.js')), // 整个目录就地压缩
            ),
            'F:\PDC\ProjectEnv\xcall150505\Public\Theme\XCall\Soui3.0b\Script\frm-layout.min.js' => array(
                'F:\PDC\ProjectEnv\xcall150505\Public\Theme\XCall\Soui3.0b\Script\frm-layout.js',
                'F:\PDC\ProjectEnv\xcall150505\Public\Jquery\soui\soui-3.0a\suplugin\jquery-marqueeLeft-1.0.js',
                'F:\PDC\ProjectEnv\xcall150505\Public\Jquery\soui\soui-3.0a\suplugin\jquery-tdprogressbar-1.0.js',
            )
        ),
        'css' => array(
            'in-place-minify' => array(// 就地压缩css
                'F:\PDC\ProjectEnv\xcall150505\Public\Theme\XCall\Soui3.0b\Css\*', // 整个目录就地压缩
            ),
            'F:\PDC\ProjectEnv\xcall150505\Public\Jquery\jquery-easyui-1.4.2\themes\default\easyui.min.css' => array(
                'F:\PDC\ProjectEnv\xcall150505\Public\Jquery\jquery-easyui-1.4.2\themes\default\easyui.css',
                array('path' => 'F:\PDC\ProjectEnv\xcall150505\Public\Jquery\jquery-easyui-1.4.2\themes\icon.css', 'replaces' => array("'icons/" => "'../Icons/")), // 内容替换
            ),
        )
    ),
);

/**
 * 根据配置文件压缩和合并文件
 * @param array $config
 * @return array
 * @since 1.0 <2015-6-2> SoChishun Added.
 */
function compression($config) {
    if (!$config) {
        return array('status' => false, 'info' => '配置无效');
    }
    $out = array();
    foreach ($config as $block => $sub_config) {
        if ('js' != $block && 'css' != $block) {
            continue;
        }
        foreach ($sub_config as $min_file => $src_files) {
            $in_place_minify = 'in-place-minify' == $min_file; // 2015-6-15 是否就地压缩
            if (!$in_place_minify) {
                if (!is_dir(dirname($min_file))) {
                    $out[$min_file]['errors'][] = dirname($min_file) . ' (目录不存在)';
                    continue;
                }
                if (file_exists($min_file)) {
                    unlink($min_file); // 先删除再生成
                }
            }
            foreach ($src_files as $src_file) {
                $src_file_info = fn_get_src_file_info($src_file);
                $src_file = $src_file_info['path'];
                $skip_minize = $src_file_info['skip_minize'];
                $replaces = $src_file_info['replaces'];
                if ('*' == $src_file[strlen($src_file) - 1]) { // 2015-6-15 整个目录压缩                    
                    $skips = $src_file_info['skips'];
                    $subfiles = fn_get_files(dirname($src_file), $skips);
                    if (!is_array($subfiles)) {
                        $out[$block . '[' . $min_file . ']']['errors'][] = $subfiles;
                        continue;
                    }
                    foreach ($subfiles as $subfile) {
                        $min_file_temp = $in_place_minify ? fn_get_in_place_min_name($subfile) : $min_file;
                        if (!is_dir(dirname($min_file_temp))) {
                            $out[$min_file_temp]['errors'][] = dirname($min_file_temp) . ' (目录不存在)';
                            continue;
                        }
                        fn_minify_file($min_file_temp, $subfile, $block, $skip_minize, $replaces, $out);
                    }
                    continue;
                }
                $min_file_temp = $min_file;
                if ($in_place_minify) {
                    $min_file_temp = fn_get_in_place_min_name($src_file);
                    if (!is_dir(dirname($min_file_temp))) {
                        $out[$min_file]['errors'][] = dirname($min_file_temp) . ' (目录不存在)';
                        continue;
                    }
                    if (file_exists($min_file_temp)) {
                        unlink($min_file_temp); // 先删除再生成
                    }
                }
                fn_minify_file($min_file_temp, $src_file, $block, $skip_minize, $replaces, $out);
            }
        }
    }
    return array('status' => true, 'info' => $out);
}

/**
 * 获取浏览器传递的参数值
 * @param string $name
 * @param string $defv
 * @return string
 * @since 1.0 <2015-6-2> SoChishun Added.
 */
function fn_request($name, $defv = '') {
    return isset($_GET[$name]) ? $_GET[$name] : $defv;
}

/**
 * 格式化字节大小
 * @param  number $size      字节数
 * @param  string $delimiter 数字和单位分隔符
 * @return string            格式化后的带单位的大小
 * @author 麦当苗儿 <zuojiazi@vip.qq.com>
 */
function fn_format_bytes($size, $delimiter = '') {
    $units = array('B', 'KB', 'MB', 'GB', 'TB', 'PB');
    for ($i = 0; $size >= 1024 && $i < 5; $i++)
        $size /= 1024;
    return round($size, 2) . $delimiter . $units[$i];
}

/**
 * 返回目录中所有文件
 * @param string $dir
 * @param array $skips
 * @return string|array
 * @since 1.0 <2015-6-15> SoChishun Added.
 */
function fn_get_files($dir, $skips = false) {
    if (!is_dir($dir)) {
        return $dir . '(不是有效目录)';
    }
    if (false != ($handle = opendir($dir))) {
        while (false != ($file = readdir($handle))) {
            if ('.' == $file || '..' == $file || false === strpos($file, '.')) {
                continue;
            }
            $path = $dir . DIRECTORY_SEPARATOR . $file;

            if ($skips && in_array($path, $skips)) {
                continue;
            }
            $files[] = $path;
        }
        closedir($handle);
    }
    return $files ? $files : $dir . '(空目录)';
}

/**
 * 压缩文件
 * @param string $min_file
 * @param string $src_file
 * @param string $block
 * @param boolean $skip_minize
 * @param array $replaces
 * @param array $info
 * @since 1.0 <2015-6-15> SoChishun Added.
 */
function fn_minify_file($min_file, $src_file, $block, $skip_minize, $replaces, &$info) {
    if (false !== strpos($src_file, '.min.')) {
        return;
    }
    if (!isset($info[$min_file]['size'])) {
        $info[$min_file]['size'] = 0;
    }
    if (file_exists($src_file)) {
        $info[$min_file]['files'][] = array('name' => $src_file, 'size' => filesize($src_file));
        $temp = file_get_contents($src_file);
        if ($temp) {
            if (!empty($replaces)) {
                foreach ($replaces as $key => $value) {
                    $temp = str_replace($key, $value, $temp);
                }
            }
            if (!$skip_minize) {
                switch ($block) {
                    case 'js':
                        $temp = JSMin::minify($temp);
                        break;
                    case 'css':
                        $cssMin = new CSSmin();
                        $temp = $cssMin->run($temp);
                        break;
                }
            }
            $info[$min_file]['size'] += file_put_contents($min_file, trim($temp), FILE_APPEND);
            $temp = null;
        }
    } else {
        $info[$min_file]['errors'][] = $src_file . ' (不存在)';
    }
}

/**
 * 获取压缩文件名
 * @param string $src_file
 * @param boolean $unlink
 * @return string
 * @since 1.0 <2015-6-15> SoChishun Added.
 */
function fn_get_in_place_min_name($src_file, $unlink = true) {
    $min_file = substr_replace($src_file, '.min', strrpos($src_file, '.'), 0); // 2015-6-15 就地压缩, 自动构建文件名
    if ($unlink && file_exists($min_file)) {
        unlink($min_file); // min_file文件先删除再生成
    }
    return $min_file;
}

/**
 * 获取源文件信息
 * @param string|array $src_file
 * @return array
 * @since 1.0 <2015-6-15> SoChishun Added.
 */
function fn_get_src_file_info($src_file) {
    $skip_minize = false; // 2015-6-8 不压缩
    $replaces = false; // 2015-6-6 内容替换
    $skips = false; // 2015-6-15 忽略操作
    if (is_array($src_file)) {
        if (!empty($src_file['replaces'])) {
            $replaces = $src_file['replaces'];
        }
        if (isset($src_file['minify']) && false === $src_file['minify']) {
            $skip_minize = true;
        }
        if (!empty($src_file['skips'])) {
            $skips = $src_file['skips'];
        }
        $src_file = $src_file['path'];
    }
    return array('path' => $src_file, 'skip_minize' => $skip_minize, 'replaces' => $replaces, 'skips' => $skips);
}

$id = fn_request('id');
?>
<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>suMinify <?php echo $ver; ?></title>
        <style type="text/css">
            html { margin:0px; font-size:12px;}
            .error { color:#F00; margin:5px 0px; font-weight: bold;}
            .success{ color:#090; margin:5px 0px; font-weight: bold;}
            table { border:solid 1px #CCC; border-right: none; border-bottom: none;}
            th, td { border:solid 1px #CCC; border-top:none; border-left:none; padding:5px; line-height: 18px;}
            td .error { font-weight:normal;}
        </style>
    </head>
    <body>
        <h1>suMinify Javascript||Css文件合并压缩工具</h1>
        <form method="get" action="suMinify.php">
            <?php
            echo '选择项目：<select name="id"><option>==选择==</option>';
            $keys = array_keys($config);
            foreach ($keys as $key) {
                echo '<option value="', $key, '"', ($id == $key ? ' selected="selected"' : ''), '>', $key, '</option>';
            }
            echo '</select>';
            ?>            
            <input type="submit" value="开始生成" />
            <input type="hidden" name="run" value="y" />
        </form>
        <?php
        if ('y' == fn_request('run') && $id) {
            if (array_key_exists($id, $config)) {
                $datas = $config[$id];
                if (!is_array($datas)) {
                    if (!file_exists($datas)) {
                        die('项目配置文件路径不存在!');
                    }
                    $datas = require $datas;
                    if (!$datas) {
                        die('项目配置文件内容无效!');
                    }
                }
                $result = compression($datas);
                if ($result['status']) {
                    $info = $result['info'];
                    $sum = array('min_size_total' => 0, 'src_size_total' => 0, 'diff_size_total' => 0, 'diff_rate_total' => 0); // 统计
                    echo '<div class="success">生成成功</div>';
                    echo '<table cellspacing="0" border="0"><tr><th>生成目标文件</th><th>源文件</th><th>压缩量 / 压缩率</th></tr>';
                    foreach ($info as $min_file => $data) {
                        echo '<tr><td>', $min_file, '<br /><strong>大小：', (empty($data['size']) ? 0 : fn_format_bytes($data['size'])), '</strong></td><td>';
                        $diffsize = 0;
                        $diffrate = 0;
                        if (!empty($data['files'])) {
                            $filesize = 0;
                            $files = $data['files'];
                            foreach ($files as $file) {
                                $filesize+=$file['size'];
                                echo $file['name'], ' (', fn_format_bytes($file['size']), ')<br />';
                            }
                            echo '<strong>总大小：', fn_format_bytes($filesize), '</strong>';
                            $diffsize = $filesize - $data['size'];
                            $sum['min_size_total']+=$data['size'];
                            $sum['src_size_total']+=$filesize;
                            $sum['diff_size_total']+=$diffsize;
                            $diffrate = round($diffsize * 100 / $filesize, 2) . '%';
                            $diffsize = fn_format_bytes($diffsize);
                        }
                        // 错误消息
                        if (!empty($data['errors'])) {
                            echo '<div class="error">', implode('<br >', $data['errors']), '</div>';
                        }
                        echo '</td><td>', $diffsize, ' / ', $diffrate, '</td></tr>';
                    }
                    $diff_rate_total = 0;
                    if ($sum['min_size_total']) {
                        $diff_rate_total = round($sum['diff_size_total'] * 100 / $sum['src_size_total'], 2) . '%';
                    }
                    echo '<tr><th>总共：', fn_format_bytes($sum['min_size_total']), '</th><th>总共：', fn_format_bytes($sum['src_size_total']), '</th><th>', fn_format_bytes($sum['diff_size_total']), ' / ', $diff_rate_total, '</th></tr>';
                    echo '</table>';
                } else {
                    echo '<div class="error">生成失败:' . $result['info'] . '!</div>';
                }
            } else {
                echo '<div class="error">项目不存在!</div>';
            }
        }
        ?>
    </body>
</html>
<?php

/**
 * jsmin.php - PHP implementation of Douglas Crockford's JSMin.
 *
 * This is pretty much a direct port of jsmin.c to PHP with just a few
 * PHP-specific performance tweaks. Also, whereas jsmin.c reads from stdin and
 * outputs to stdout, this library accepts a string as input and returns another
 * string as output.
 *
 * PHP 5 or higher is required.
 *
 * Permission is hereby granted to use this version of the library under the
 * same terms as jsmin.c, which has the following license:
 *
 * --
 * Copyright (c) 2002 Douglas Crockford  (www.crockford.com)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is furnished to do
 * so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * The Software shall be used for Good, not Evil.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 * --
 *
 * @package JSMin
 * @author Ryan Grove <ryan@wonko.com>
 * @copyright 2002 Douglas Crockford <douglas@crockford.com> (jsmin.c)
 * @copyright 2008 Ryan Grove <ryan@wonko.com> (PHP port)
 * @copyright 2012 Adam Goforth <aag@adamgoforth.com> (Updates)
 * @license http://opensource.org/licenses/mit-license.php MIT License
 * @version 1.1.2 (2012-05-01)
 * @link https://github.com/rgrove/jsmin-php
 */
class JSMin {

    const ORD_LF = 10;
    const ORD_SPACE = 32;
    const ACTION_KEEP_A = 1;
    const ACTION_DELETE_A = 2;
    const ACTION_DELETE_A_B = 3;

    protected $a = '';
    protected $b = '';
    protected $input = '';
    protected $inputIndex = 0;
    protected $inputLength = 0;
    protected $lookAhead = null;
    protected $output = '';

    // -- Public Static Methods --------------------------------------------------

    /**
     * Minify Javascript
     *
     * @uses __construct()
     * @uses min()
     * @param string $js Javascript to be minified
     * @return string
     */
    public static function minify($js) {
        $jsmin = new JSMin($js);
        return $jsmin->min();
    }

    // -- Public Instance Methods ------------------------------------------------

    /**
     * Constructor
     *
     * @param string $input Javascript to be minified
     */
    public function __construct($input) {
        $this->input = str_replace("\r\n", "\n", $input);
        $this->inputLength = strlen($this->input);
    }

    // -- Protected Instance Methods ---------------------------------------------

    /**
     * Action -- do something! What to do is determined by the $command argument.
     *
     * action treats a string as a single character. Wow!
     * action recognizes a regular expression if it is preceded by ( or , or =.
     *
     * @uses next()
     * @uses get()
     * @throws JSMinException If parser errors are found:
     *         - Unterminated string literal
     *         - Unterminated regular expression set in regex literal
     *         - Unterminated regular expression literal
     * @param int $command One of class constants:
     *      ACTION_KEEP_A      Output A. Copy B to A. Get the next B.
     *      ACTION_DELETE_A    Copy B to A. Get the next B. (Delete A).
     *      ACTION_DELETE_A_B  Get the next B. (Delete B).
     */
    protected function action($command) {
        switch ($command) {
            case self::ACTION_KEEP_A:
                $this->output .= $this->a;

            case self::ACTION_DELETE_A:
                $this->a = $this->b;

                if ($this->a === "'" || $this->a === '"') {
                    for (;;) {
                        $this->output .= $this->a;
                        $this->a = $this->get();

                        if ($this->a === $this->b) {
                            break;
                        }

                        if (ord($this->a) <= self::ORD_LF) {
                            throw new JSMinException('Unterminated string literal.');
                        }

                        if ($this->a === '\\') {
                            $this->output .= $this->a;
                            $this->a = $this->get();
                        }
                    }
                }

            case self::ACTION_DELETE_A_B:
                $this->b = $this->next();

                if ($this->b === '/' && (
                        $this->a === '(' || $this->a === ',' || $this->a === '=' ||
                        $this->a === ':' || $this->a === '[' || $this->a === '!' ||
                        $this->a === '&' || $this->a === '|' || $this->a === '?' ||
                        $this->a === '{' || $this->a === '}' || $this->a === ';' ||
                        $this->a === "\n" )) {

                    $this->output .= $this->a . $this->b;

                    for (;;) {
                        $this->a = $this->get();

                        if ($this->a === '[') {
                            /*
                              inside a regex [...] set, which MAY contain a '/' itself. Example: mootools Form.Validator near line 460:
                              return Form.Validator.getValidator('IsEmpty').test(element) || (/^(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]\.?){0,63}[a-z0-9!#$%&'*+/=?^_`{|}~-]@(?:(?:[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?\.)*[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\])$/i).test(element.get('value'));
                             */
                            for (;;) {
                                $this->output .= $this->a;
                                $this->a = $this->get();

                                if ($this->a === ']') {
                                    break;
                                } elseif ($this->a === '\\') {
                                    $this->output .= $this->a;
                                    $this->a = $this->get();
                                } elseif (ord($this->a) <= self::ORD_LF) {
                                    throw new JSMinException('Unterminated regular expression set in regex literal.');
                                }
                            }
                        } elseif ($this->a === '/') {
                            break;
                        } elseif ($this->a === '\\') {
                            $this->output .= $this->a;
                            $this->a = $this->get();
                        } elseif (ord($this->a) <= self::ORD_LF) {
                            throw new JSMinException('Unterminated regular expression literal.');
                        }

                        $this->output .= $this->a;
                    }

                    $this->b = $this->next();
                }
        }
    }

    /**
     * Get next char. Convert ctrl char to space.
     *
     * @return string|null
     */
    protected function get() {
        $c = $this->lookAhead;
        $this->lookAhead = null;

        if ($c === null) {
            if ($this->inputIndex < $this->inputLength) {
                $c = substr($this->input, $this->inputIndex, 1);
                $this->inputIndex += 1;
            } else {
                $c = null;
            }
        }

        if ($c === "\r") {
            return "\n";
        }

        if ($c === null || $c === "\n" || ord($c) >= self::ORD_SPACE) {
            return $c;
        }

        return ' ';
    }

    /**
     * Is $c a letter, digit, underscore, dollar sign, or non-ASCII character.
     *
     * @return bool
     */
    protected function isAlphaNum($c) {
        return ord($c) > 126 || $c === '\\' || preg_match('/^[\w\$]$/', $c) === 1;
    }

    /**
     * Perform minification, return result
     *
     * @uses action()
     * @uses isAlphaNum()
     * @uses get()
     * @uses peek()
     * @return string
     */
    protected function min() {
        if (0 == strncmp($this->peek(), "\xef", 1)) {
            $this->get();
            $this->get();
            $this->get();
        }

        $this->a = "\n";
        $this->action(self::ACTION_DELETE_A_B);

        while ($this->a !== null) {
            switch ($this->a) {
                case ' ':
                    if ($this->isAlphaNum($this->b)) {
                        $this->action(self::ACTION_KEEP_A);
                    } else {
                        $this->action(self::ACTION_DELETE_A);
                    }
                    break;

                case "\n":
                    switch ($this->b) {
                        case '{':
                        case '[':
                        case '(':
                        case '+':
                        case '-':
                        case '!':
                        case '~':
                            $this->action(self::ACTION_KEEP_A);
                            break;

                        case ' ':
                            $this->action(self::ACTION_DELETE_A_B);
                            break;

                        default:
                            if ($this->isAlphaNum($this->b)) {
                                $this->action(self::ACTION_KEEP_A);
                            } else {
                                $this->action(self::ACTION_DELETE_A);
                            }
                    }
                    break;

                default:
                    switch ($this->b) {
                        case ' ':
                            if ($this->isAlphaNum($this->a)) {
                                $this->action(self::ACTION_KEEP_A);
                                break;
                            }

                            $this->action(self::ACTION_DELETE_A_B);
                            break;

                        case "\n":
                            switch ($this->a) {
                                case '}':
                                case ']':
                                case ')':
                                case '+':
                                case '-':
                                case '"':
                                case "'":
                                    $this->action(self::ACTION_KEEP_A);
                                    break;

                                default:
                                    if ($this->isAlphaNum($this->a)) {
                                        $this->action(self::ACTION_KEEP_A);
                                    } else {
                                        $this->action(self::ACTION_DELETE_A_B);
                                    }
                            }
                            break;

                        default:
                            $this->action(self::ACTION_KEEP_A);
                            break;
                    }
            }
        }

        return $this->output;
    }

    /**
     * Get the next character, skipping over comments. peek() is used to see
     *  if a '/' is followed by a '/' or '*'.
     *
     * @uses get()
     * @uses peek()
     * @throws JSMinException On unterminated comment.
     * @return string
     */
    protected function next() {
        $c = $this->get();

        if ($c === '/') {
            switch ($this->peek()) {
                case '/':
                    for (;;) {
                        $c = $this->get();

                        if (ord($c) <= self::ORD_LF) {
                            return $c;
                        }
                    }

                case '*':
                    $this->get();

                    for (;;) {
                        switch ($this->get()) {
                            case '*':
                                if ($this->peek() === '/') {
                                    $this->get();
                                    return ' ';
                                }
                                break;

                            case null:
                                throw new JSMinException('Unterminated comment.');
                        }
                    }

                default:
                    return $c;
            }
        }

        return $c;
    }

    /**
     * Get next char. If is ctrl character, translate to a space or newline.
     *
     * @uses get()
     * @return string|null
     */
    protected function peek() {
        $this->lookAhead = $this->get();
        return $this->lookAhead;
    }

}

// -- Exceptions ---------------------------------------------------------------
class JSMinException extends Exception {
    
}

/* !
 * cssmin.php v2.4.8-4
 * Author: Tubal Martin - http://tubalmartin.me/
 * Repo: https://github.com/tubalmartin/YUI-CSS-compressor-PHP-port
 *
 * This is a PHP port of the CSS minification tool distributed with YUICompressor,
 * itself a port of the cssmin utility by Isaac Schlueter - http://foohack.com/
 * Permission is hereby granted to use the PHP version under the same
 * conditions as the YUICompressor.
 */
/* !
 * YUI Compressor
 * http://developer.yahoo.com/yui/compressor/
 * Author: Julien Lecomte - http://www.julienlecomte.net/
 * Copyright (c) 2013 Yahoo! Inc. All rights reserved.
 * The copyrights embodied in the content of this file are licensed
 * by Yahoo! Inc. under the BSD (revised) open source license.
 */

class CSSmin {

    const NL = '___YUICSSMIN_PRESERVED_NL___';
    const TOKEN = '___YUICSSMIN_PRESERVED_TOKEN_';
    const COMMENT = '___YUICSSMIN_PRESERVE_CANDIDATE_COMMENT_';
    const CLASSCOLON = '___YUICSSMIN_PSEUDOCLASSCOLON___';
    const QUERY_FRACTION = '___YUICSSMIN_QUERY_FRACTION___';

    private $comments;
    private $preserved_tokens;
    private $memory_limit;
    private $max_execution_time;
    private $pcre_backtrack_limit;
    private $pcre_recursion_limit;
    private $raise_php_limits;

    /**
     * @param bool|int $raise_php_limits
     * If true, PHP settings will be raised if needed
     */
    public function __construct($raise_php_limits = TRUE) {
        // Set suggested PHP limits
        $this->memory_limit = 128 * 1048576; // 128MB in bytes
        $this->max_execution_time = 60; // 1 min
        $this->pcre_backtrack_limit = 1000 * 1000;
        $this->pcre_recursion_limit = 500 * 1000;
        $this->raise_php_limits = (bool) $raise_php_limits;
    }

    /**
     * Minify a string of CSS
     * @param string $css
     * @param int|bool $linebreak_pos
     * @return string
     */
    public function run($css = '', $linebreak_pos = FALSE) {
        if (empty($css)) {
            return '';
        }
        if ($this->raise_php_limits) {
            $this->do_raise_php_limits();
        }
        $this->comments = array();
        $this->preserved_tokens = array();
        $start_index = 0;
        $length = strlen($css);
        $css = $this->extract_data_urls($css);
        // collect all comment blocks...
        while (($start_index = $this->index_of($css, '/*', $start_index)) >= 0) {
            $end_index = $this->index_of($css, '*/', $start_index + 2);
            if ($end_index < 0) {
                $end_index = $length;
            }
            $comment_found = $this->str_slice($css, $start_index + 2, $end_index);
            $this->comments[] = $comment_found;
            $comment_preserve_string = self::COMMENT . (count($this->comments) - 1) . '___';
            $css = $this->str_slice($css, 0, $start_index + 2) . $comment_preserve_string . $this->str_slice($css, $end_index);
            // Set correct start_index: Fixes issue #2528130
            $start_index = $end_index + 2 + strlen($comment_preserve_string) - strlen($comment_found);
        }
        // preserve strings so their content doesn't get accidentally minified
        $css = preg_replace_callback('/(?:"(?:[^\\\\"]|\\\\.|\\\\)*")|' . "(?:'(?:[^\\\\']|\\\\.|\\\\)*')/S", array($this, 'replace_string'), $css);
        // Let's divide css code in chunks of 5.000 chars aprox.
        // Reason: PHP's PCRE functions like preg_replace have a "backtrack limit"
        // of 100.000 chars by default (php < 5.3.7) so if we're dealing with really
        // long strings and a (sub)pattern matches a number of chars greater than
        // the backtrack limit number (i.e. /(.*)/s) PCRE functions may fail silently
        // returning NULL and $css would be empty.
        $charset = '';
        $charset_regexp = '/(@charset)( [^;]+;)/i';
        $css_chunks = array();
        $css_chunk_length = 5000; // aprox size, not exact
        $start_index = 0;
        $i = $css_chunk_length; // save initial iterations
        $l = strlen($css);
        // if the number of characters is 5000 or less, do not chunk
        if ($l <= $css_chunk_length) {
            $css_chunks[] = $css;
        } else {
            // chunk css code securely
            while ($i < $l) {
                $i += 50; // save iterations
                if ($l - $start_index <= $css_chunk_length || $i >= $l) {
                    $css_chunks[] = $this->str_slice($css, $start_index);
                    break;
                }
                if ($css[$i - 1] === '}' && $i - $start_index > $css_chunk_length) {
                    // If there are two ending curly braces }} separated or not by spaces,
                    // join them in the same chunk (i.e. @media blocks)
                    $next_chunk = substr($css, $i);
                    if (preg_match('/^\s*\}/', $next_chunk)) {
                        $i = $i + $this->index_of($next_chunk, '}') + 1;
                    }
                    $css_chunks[] = $this->str_slice($css, $start_index, $i);
                    $start_index = $i;
                }
            }
        }
        // Minify each chunk
        for ($i = 0, $n = count($css_chunks); $i < $n; $i++) {
            $css_chunks[$i] = $this->minify($css_chunks[$i], $linebreak_pos);
            // Keep the first @charset at-rule found
            if (empty($charset) && preg_match($charset_regexp, $css_chunks[$i], $matches)) {
                $charset = strtolower($matches[1]) . $matches[2];
            }
            // Delete all @charset at-rules
            $css_chunks[$i] = preg_replace($charset_regexp, '', $css_chunks[$i]);
        }
        // Update the first chunk and push the charset to the top of the file.
        $css_chunks[0] = $charset . $css_chunks[0];
        return implode('', $css_chunks);
    }

    /**
     * Sets the memory limit for this script
     * @param int|string $limit
     */
    public function set_memory_limit($limit) {
        $this->memory_limit = $this->normalize_int($limit);
    }

    /**
     * Sets the maximum execution time for this script
     * @param int|string $seconds
     */
    public function set_max_execution_time($seconds) {
        $this->max_execution_time = (int) $seconds;
    }

    /**
     * Sets the PCRE backtrack limit for this script
     * @param int $limit
     */
    public function set_pcre_backtrack_limit($limit) {
        $this->pcre_backtrack_limit = (int) $limit;
    }

    /**
     * Sets the PCRE recursion limit for this script
     * @param int $limit
     */
    public function set_pcre_recursion_limit($limit) {
        $this->pcre_recursion_limit = (int) $limit;
    }

    /**
     * Try to configure PHP to use at least the suggested minimum settings
     */
    private function do_raise_php_limits() {
        $php_limits = array(
            'memory_limit' => $this->memory_limit,
            'max_execution_time' => $this->max_execution_time,
            'pcre.backtrack_limit' => $this->pcre_backtrack_limit,
            'pcre.recursion_limit' => $this->pcre_recursion_limit
        );
        // If current settings are higher respect them.
        foreach ($php_limits as $name => $suggested) {
            $current = $this->normalize_int(ini_get($name));
            // memory_limit exception: allow -1 for "no memory limit".
            if ($current > -1 && ($suggested == -1 || $current < $suggested)) {
                ini_set($name, $suggested);
            }
        }
    }

    /**
     * Does bulk of the minification
     * @param string $css
     * @param int|bool $linebreak_pos
     * @return string
     */
    private function minify($css, $linebreak_pos) {
        // strings are safe, now wrestle the comments
        for ($i = 0, $max = count($this->comments); $i < $max; $i++) {
            $token = $this->comments[$i];
            $placeholder = '/' . self::COMMENT . $i . '___/';
            // ! in the first position of the comment means preserve
            // so push to the preserved tokens keeping the !
            if (substr($token, 0, 1) === '!') {
                $this->preserved_tokens[] = $token;
                $token_tring = self::TOKEN . (count($this->preserved_tokens) - 1) . '___';
                $css = preg_replace($placeholder, $token_tring, $css, 1);
                // Preserve new lines for /*! important comments
                $css = preg_replace('/\s*[\n\r\f]+\s*(\/\*' . $token_tring . ')/S', self::NL . '$1', $css);
                $css = preg_replace('/(' . $token_tring . '\*\/)\s*[\n\r\f]+\s*/', '$1' . self::NL, $css);
                continue;
            }
            // \ in the last position looks like hack for Mac/IE5
            // shorten that to /*\*/ and the next one to /**/
            if (substr($token, (strlen($token) - 1), 1) === '\\') {
                $this->preserved_tokens[] = '\\';
                $css = preg_replace($placeholder, self::TOKEN . (count($this->preserved_tokens) - 1) . '___', $css, 1);
                $i = $i + 1; // attn: advancing the loop
                $this->preserved_tokens[] = '';
                $css = preg_replace('/' . self::COMMENT . $i . '___/', self::TOKEN . (count($this->preserved_tokens) - 1) . '___', $css, 1);
                continue;
            }
            // keep empty comments after child selectors (IE7 hack)
            // e.g. html >/**/ body
            if (strlen($token) === 0) {
                $start_index = $this->index_of($css, $this->str_slice($placeholder, 1, -1));
                if ($start_index > 2) {
                    if (substr($css, $start_index - 3, 1) === '>') {
                        $this->preserved_tokens[] = '';
                        $css = preg_replace($placeholder, self::TOKEN . (count($this->preserved_tokens) - 1) . '___', $css, 1);
                    }
                }
            }
            // in all other cases kill the comment
            $css = preg_replace('/\/\*' . $this->str_slice($placeholder, 1, -1) . '\*\//', '', $css, 1);
        }
        // Normalize all whitespace strings to single spaces. Easier to work with that way.
        $css = preg_replace('/\s+/', ' ', $css);
        // Fix IE7 issue on matrix filters which browser accept whitespaces between Matrix parameters
        $css = preg_replace_callback('/\s*filter\:\s*progid:DXImageTransform\.Microsoft\.Matrix\(([^\)]+)\)/', array($this, 'preserve_old_IE_specific_matrix_definition'), $css);
        // Shorten & preserve calculations calc(...) since spaces are important
        $css = preg_replace_callback('/calc(\(((?:[^\(\)]+|(?1))*)\))/i', array($this, 'replace_calc'), $css);
        // Replace positive sign from numbers preceded by : or a white-space before the leading space is removed
        // +1.2em to 1.2em, +.8px to .8px, +2% to 2%
        $css = preg_replace('/((?<!\\\\)\:|\s)\+(\.?\d+)/S', '$1$2', $css);
        // Remove leading zeros from integer and float numbers preceded by : or a white-space
        // 000.6 to .6, -0.8 to -.8, 0050 to 50, -01.05 to -1.05
        $css = preg_replace('/((?<!\\\\)\:|\s)(\-?)0+(\.?\d+)/S', '$1$2$3', $css);
        // Remove trailing zeros from float numbers preceded by : or a white-space
        // -6.0100em to -6.01em, .0100 to .01, 1.200px to 1.2px
        $css = preg_replace('/((?<!\\\\)\:|\s)(\-?)(\d?\.\d+?)0+([^\d])/S', '$1$2$3$4', $css);
        // Remove trailing .0 -> -9.0 to -9
        $css = preg_replace('/((?<!\\\\)\:|\s)(\-?\d+)\.0([^\d])/S', '$1$2$3', $css);
        // Replace 0 length numbers with 0
        $css = preg_replace('/((?<!\\\\)\:|\s)\-?\.?0+([^\d])/S', '${1}0$2', $css);
        // Remove the spaces before the things that should not have spaces before them.
        // But, be careful not to turn "p :link {...}" into "p:link{...}"
        // Swap out any pseudo-class colons with the token, and then swap back.
        $css = preg_replace_callback('/(?:^|\})[^\{]*\s+\:/', array($this, 'replace_colon'), $css);
        // Remove spaces before the things that should not have spaces before them.
        $css = preg_replace('/\s+([\!\{\}\;\:\>\+\(\)\]\~\=,])/', '$1', $css);
        // Restore spaces for !important
        $css = preg_replace('/\!important/i', ' !important', $css);
        // bring back the colon
        $css = preg_replace('/' . self::CLASSCOLON . '/', ':', $css);
        // retain space for special IE6 cases
        $css = preg_replace_callback('/\:first\-(line|letter)(\{|,)/i', array($this, 'lowercase_pseudo_first'), $css);
        // no space after the end of a preserved comment
        $css = preg_replace('/\*\/ /', '*/', $css);
        // lowercase some popular @directives
        $css = preg_replace_callback('/@(font-face|import|(?:-(?:atsc|khtml|moz|ms|o|wap|webkit)-)?keyframe|media|page|namespace)/i', array($this, 'lowercase_directives'), $css);
        // lowercase some more common pseudo-elements
        $css = preg_replace_callback('/:(active|after|before|checked|disabled|empty|enabled|first-(?:child|of-type)|focus|hover|last-(?:child|of-type)|link|only-(?:child|of-type)|root|:selection|target|visited)/i', array($this, 'lowercase_pseudo_elements'), $css);
        // lowercase some more common functions
        $css = preg_replace_callback('/:(lang|not|nth-child|nth-last-child|nth-last-of-type|nth-of-type|(?:-(?:moz|webkit)-)?any)\(/i', array($this, 'lowercase_common_functions'), $css);
        // lower case some common function that can be values
        // NOTE: rgb() isn't useful as we replace with #hex later, as well as and() is already done for us
        $css = preg_replace_callback('/([:,\( ]\s*)(attr|color-stop|from|rgba|to|url|(?:-(?:atsc|khtml|moz|ms|o|wap|webkit)-)?(?:calc|max|min|(?:repeating-)?(?:linear|radial)-gradient)|-webkit-gradient)/iS', array($this, 'lowercase_common_functions_values'), $css);
        // Put the space back in some cases, to support stuff like
        // @media screen and (-webkit-min-device-pixel-ratio:0){
        $css = preg_replace('/\band\(/i', 'and (', $css);
        // Remove the spaces after the things that should not have spaces after them.
        $css = preg_replace('/([\!\{\}\:;\>\+\(\[\~\=,])\s+/S', '$1', $css);
        // remove unnecessary semicolons
        $css = preg_replace('/;+\}/', '}', $css);
        // Fix for issue: #2528146
        // Restore semicolon if the last property is prefixed with a `*` (lte IE7 hack)
        // to avoid issues on Symbian S60 3.x browsers.
        $css = preg_replace('/(\*[a-z0-9\-]+\s*\:[^;\}]+)(\})/', '$1;$2', $css);
        // Replace 0 <length> and 0 <percentage> values with 0.
        // <length> data type: https://developer.mozilla.org/en-US/docs/Web/CSS/length
        // <percentage> data type: https://developer.mozilla.org/en-US/docs/Web/CSS/percentage
        $css = preg_replace('/([^\\\\]\:|\s)0(?:em|ex|ch|rem|vw|vh|vm|vmin|cm|mm|in|px|pt|pc|%)/iS', '${1}0', $css);
        // 0% step in a keyframe? restore the % unit
        $css = preg_replace_callback('/(@[a-z\-]*?keyframes[^\{]+\{)(.*?)(\}\})/iS', array($this, 'replace_keyframe_zero'), $css);
        // Replace 0 0; or 0 0 0; or 0 0 0 0; with 0.
        $css = preg_replace('/\:0(?: 0){1,3}(;|\}| \!)/', ':0$1', $css);
        // Fix for issue: #2528142
        // Replace text-shadow:0; with text-shadow:0 0 0;
        $css = preg_replace('/(text-shadow\:0)(;|\}| \!)/i', '$1 0 0$2', $css);
        // Replace background-position:0; with background-position:0 0;
        // same for transform-origin
        // Changing -webkit-mask-position: 0 0 to just a single 0 will result in the second parameter defaulting to 50% (center)
        $css = preg_replace('/(background\-position|webkit-mask-position|(?:webkit|moz|o|ms|)\-?transform\-origin)\:0(;|\}| \!)/iS', '$1:0 0$2', $css);
        // Shorten colors from rgb(51,102,153) to #336699, rgb(100%,0%,0%) to #ff0000 (sRGB color space)
        // Shorten colors from hsl(0, 100%, 50%) to #ff0000 (sRGB color space)
        // This makes it more likely that it'll get further compressed in the next step.
        $css = preg_replace_callback('/rgb\s*\(\s*([0-9,\s\-\.\%]+)\s*\)(.{1})/i', array($this, 'rgb_to_hex'), $css);
        $css = preg_replace_callback('/hsl\s*\(\s*([0-9,\s\-\.\%]+)\s*\)(.{1})/i', array($this, 'hsl_to_hex'), $css);
        // Shorten colors from #AABBCC to #ABC or short color name.
        $css = $this->compress_hex_colors($css);
        // border: none to border:0, outline: none to outline:0
        $css = preg_replace('/(border\-?(?:top|right|bottom|left|)|outline)\:none(;|\}| \!)/iS', '$1:0$2', $css);
        // shorter opacity IE filter
        $css = preg_replace('/progid\:DXImageTransform\.Microsoft\.Alpha\(Opacity\=/i', 'alpha(opacity=', $css);
        // Find a fraction that is used for Opera's -o-device-pixel-ratio query
        // Add token to add the "\" back in later
        $css = preg_replace('/\(([a-z\-]+):([0-9]+)\/([0-9]+)\)/i', '($1:$2' . self::QUERY_FRACTION . '$3)', $css);
        // Remove empty rules.
        $css = preg_replace('/[^\};\{\/]+\{\}/S', '', $css);
        // Add "/" back to fix Opera -o-device-pixel-ratio query
        $css = preg_replace('/' . self::QUERY_FRACTION . '/', '/', $css);
        // Replace multiple semi-colons in a row by a single one
        // See SF bug #1980989
        $css = preg_replace('/;;+/', ';', $css);
        // Restore new lines for /*! important comments
        $css = preg_replace('/' . self::NL . '/', "\n", $css);
        // Lowercase all uppercase properties
        $css = preg_replace_callback('/(\{|\;)([A-Z\-]+)(\:)/', array($this, 'lowercase_properties'), $css);
        // Some source control tools don't like it when files containing lines longer
        // than, say 8000 characters, are checked in. The linebreak option is used in
        // that case to split long lines after a specific column.
        if ($linebreak_pos !== FALSE && (int) $linebreak_pos >= 0) {
            $linebreak_pos = (int) $linebreak_pos;
            $start_index = $i = 0;
            while ($i < strlen($css)) {
                $i++;
                if ($css[$i - 1] === '}' && $i - $start_index > $linebreak_pos) {
                    $css = $this->str_slice($css, 0, $i) . "\n" . $this->str_slice($css, $i);
                    $start_index = $i;
                }
            }
        }
        // restore preserved comments and strings in reverse order
        for ($i = count($this->preserved_tokens) - 1; $i >= 0; $i--) {
            $css = preg_replace('/' . self::TOKEN . $i . '___/', $this->preserved_tokens[$i], $css, 1);
        }
        // Trim the final string (for any leading or trailing white spaces)
        return trim($css);
    }

    /**
     * Utility method to replace all data urls with tokens before we start
     * compressing, to avoid performance issues running some of the subsequent
     * regexes against large strings chunks.
     *
     * @param string $css
     * @return string
     */
    private function extract_data_urls($css) {
        // Leave data urls alone to increase parse performance.
        $max_index = strlen($css) - 1;
        $append_index = $index = $last_index = $offset = 0;
        $sb = array();
        $pattern = '/url\(\s*(["\']?)data\:/i';
        // Since we need to account for non-base64 data urls, we need to handle
        // ' and ) being part of the data string. Hence switching to indexOf,
        // to determine whether or not we have matching string terminators and
        // handling sb appends directly, instead of using matcher.append* methods.
        while (preg_match($pattern, $css, $m, 0, $offset)) {
            $index = $this->index_of($css, $m[0], $offset);
            $last_index = $index + strlen($m[0]);
            $start_index = $index + 4; // "url(".length()
            $end_index = $last_index - 1;
            $terminator = $m[1]; // ', " or empty (not quoted)
            $found_terminator = FALSE;
            if (strlen($terminator) === 0) {
                $terminator = ')';
            }
            while ($found_terminator === FALSE && $end_index + 1 <= $max_index) {
                $end_index = $this->index_of($css, $terminator, $end_index + 1);
                // endIndex == 0 doesn't really apply here
                if ($end_index > 0 && substr($css, $end_index - 1, 1) !== '\\') {
                    $found_terminator = TRUE;
                    if (')' != $terminator) {
                        $end_index = $this->index_of($css, ')', $end_index);
                    }
                }
            }
            // Enough searching, start moving stuff over to the buffer
            $sb[] = $this->str_slice($css, $append_index, $index);
            if ($found_terminator) {
                $token = $this->str_slice($css, $start_index, $end_index);
                $token = preg_replace('/\s+/', '', $token);
                $this->preserved_tokens[] = $token;
                $preserver = 'url(' . self::TOKEN . (count($this->preserved_tokens) - 1) . '___)';
                $sb[] = $preserver;
                $append_index = $end_index + 1;
            } else {
                // No end terminator found, re-add the whole match. Should we throw/warn here?
                $sb[] = $this->str_slice($css, $index, $last_index);
                $append_index = $last_index;
            }
            $offset = $last_index;
        }
        $sb[] = $this->str_slice($css, $append_index);
        return implode('', $sb);
    }

    /**
     * Utility method to compress hex color values of the form #AABBCC to #ABC or short color name.
     *
     * DOES NOT compress CSS ID selectors which match the above pattern (which would break things).
     * e.g. #AddressForm { ... }
     *
     * DOES NOT compress IE filters, which have hex color values (which would break things).
     * e.g. filter: chroma(color="#FFFFFF");
     *
     * DOES NOT compress invalid hex values.
     * e.g. background-color: #aabbccdd
     *
     * @param string $css
     * @return string
     */
    private function compress_hex_colors($css) {
        // Look for hex colors inside { ... } (to avoid IDs) and which don't have a =, or a " in front of them (to avoid filters)
        $pattern = '/(\=\s*?["\']?)?#([0-9a-f])([0-9a-f])([0-9a-f])([0-9a-f])([0-9a-f])([0-9a-f])(\}|[^0-9a-f{][^{]*?\})/iS';
        $_index = $index = $last_index = $offset = 0;
        $sb = array();
        // See: http://ajaxmin.codeplex.com/wikipage?title=CSS%20Colors
        $short_safe = array(
            '#808080' => 'gray',
            '#008000' => 'green',
            '#800000' => 'maroon',
            '#000080' => 'navy',
            '#808000' => 'olive',
            '#ffa500' => 'orange',
            '#800080' => 'purple',
            '#c0c0c0' => 'silver',
            '#008080' => 'teal',
            '#f00' => 'red'
        );
        while (preg_match($pattern, $css, $m, 0, $offset)) {
            $index = $this->index_of($css, $m[0], $offset);
            $last_index = $index + strlen($m[0]);
            $is_filter = $m[1] !== null && $m[1] !== '';
            $sb[] = $this->str_slice($css, $_index, $index);
            if ($is_filter) {
                // Restore, maintain case, otherwise filter will break
                $sb[] = $m[1] . '#' . $m[2] . $m[3] . $m[4] . $m[5] . $m[6] . $m[7];
            } else {
                if (strtolower($m[2]) == strtolower($m[3]) &&
                        strtolower($m[4]) == strtolower($m[5]) &&
                        strtolower($m[6]) == strtolower($m[7])) {
                    // Compress.
                    $hex = '#' . strtolower($m[3] . $m[5] . $m[7]);
                } else {
                    // Non compressible color, restore but lower case.
                    $hex = '#' . strtolower($m[2] . $m[3] . $m[4] . $m[5] . $m[6] . $m[7]);
                }
                // replace Hex colors to short safe color names
                $sb[] = array_key_exists($hex, $short_safe) ? $short_safe[$hex] : $hex;
            }
            $_index = $offset = $last_index - strlen($m[8]);
        }
        $sb[] = $this->str_slice($css, $_index);
        return implode('', $sb);
    }

    /* CALLBACKS
     * ---------------------------------------------------------------------------------------------
     */

    private function replace_string($matches) {
        $match = $matches[0];
        $quote = substr($match, 0, 1);
        // Must use addcslashes in PHP to avoid parsing of backslashes
        $match = addcslashes($this->str_slice($match, 1, -1), '\\');
        // maybe the string contains a comment-like substring?
        // one, maybe more? put'em back then
        if (($pos = $this->index_of($match, self::COMMENT)) >= 0) {
            for ($i = 0, $max = count($this->comments); $i < $max; $i++) {
                $match = preg_replace('/' . self::COMMENT . $i . '___/', $this->comments[$i], $match, 1);
            }
        }
        // minify alpha opacity in filter strings
        $match = preg_replace('/progid\:DXImageTransform\.Microsoft\.Alpha\(Opacity\=/i', 'alpha(opacity=', $match);
        $this->preserved_tokens[] = $match;
        return $quote . self::TOKEN . (count($this->preserved_tokens) - 1) . '___' . $quote;
    }

    private function replace_colon($matches) {
        return preg_replace('/\:/', self::CLASSCOLON, $matches[0]);
    }

    private function replace_calc($matches) {
        $this->preserved_tokens[] = trim(preg_replace('/\s*([\*\/\(\),])\s*/', '$1', $matches[2]));
        return 'calc(' . self::TOKEN . (count($this->preserved_tokens) - 1) . '___' . ')';
    }

    private function preserve_old_IE_specific_matrix_definition($matches) {
        $this->preserved_tokens[] = $matches[1];
        return 'filter:progid:DXImageTransform.Microsoft.Matrix(' . self::TOKEN . (count($this->preserved_tokens) - 1) . '___' . ')';
    }

    private function replace_keyframe_zero($matches) {
        return $matches[1] . preg_replace('/0(\{|,[^\)\{]+\{)/', '0%$1', $matches[2]) . $matches[3];
    }

    private function rgb_to_hex($matches) {
        // Support for percentage values rgb(100%, 0%, 45%);
        if ($this->index_of($matches[1], '%') >= 0) {
            $rgbcolors = explode(',', str_replace('%', '', $matches[1]));
            for ($i = 0; $i < count($rgbcolors); $i++) {
                $rgbcolors[$i] = $this->round_number(floatval($rgbcolors[$i]) * 2.55);
            }
        } else {
            $rgbcolors = explode(',', $matches[1]);
        }
        // Values outside the sRGB color space should be clipped (0-255)
        for ($i = 0; $i < count($rgbcolors); $i++) {
            $rgbcolors[$i] = $this->clamp_number(intval($rgbcolors[$i], 10), 0, 255);
            $rgbcolors[$i] = sprintf("%02x", $rgbcolors[$i]);
        }
        // Fix for issue #2528093
        if (!preg_match('/[\s\,\);\}]/', $matches[2])) {
            $matches[2] = ' ' . $matches[2];
        }
        return '#' . implode('', $rgbcolors) . $matches[2];
    }

    private function hsl_to_hex($matches) {
        $values = explode(',', str_replace('%', '', $matches[1]));
        $h = floatval($values[0]);
        $s = floatval($values[1]);
        $l = floatval($values[2]);
        // Wrap and clamp, then fraction!
        $h = ((($h % 360) + 360) % 360) / 360;
        $s = $this->clamp_number($s, 0, 100) / 100;
        $l = $this->clamp_number($l, 0, 100) / 100;
        if ($s == 0) {
            $r = $g = $b = $this->round_number(255 * $l);
        } else {
            $v2 = $l < 0.5 ? $l * (1 + $s) : ($l + $s) - ($s * $l);
            $v1 = (2 * $l) - $v2;
            $r = $this->round_number(255 * $this->hue_to_rgb($v1, $v2, $h + (1 / 3)));
            $g = $this->round_number(255 * $this->hue_to_rgb($v1, $v2, $h));
            $b = $this->round_number(255 * $this->hue_to_rgb($v1, $v2, $h - (1 / 3)));
        }
        return $this->rgb_to_hex(array('', $r . ',' . $g . ',' . $b, $matches[2]));
    }

    private function lowercase_pseudo_first($matches) {
        return ':first-' . strtolower($matches[1]) . ' ' . $matches[2];
    }

    private function lowercase_directives($matches) {
        return '@' . strtolower($matches[1]);
    }

    private function lowercase_pseudo_elements($matches) {
        return ':' . strtolower($matches[1]);
    }

    private function lowercase_common_functions($matches) {
        return ':' . strtolower($matches[1]) . '(';
    }

    private function lowercase_common_functions_values($matches) {
        return $matches[1] . strtolower($matches[2]);
    }

    private function lowercase_properties($matches) {
        return $matches[1] . strtolower($matches[2]) . $matches[3];
    }

    /* HELPERS
     * ---------------------------------------------------------------------------------------------
     */

    private function hue_to_rgb($v1, $v2, $vh) {
        $vh = $vh < 0 ? $vh + 1 : ($vh > 1 ? $vh - 1 : $vh);
        if ($vh * 6 < 1)
            return $v1 + ($v2 - $v1) * 6 * $vh;
        if ($vh * 2 < 1)
            return $v2;
        if ($vh * 3 < 2)
            return $v1 + ($v2 - $v1) * ((2 / 3) - $vh) * 6;
        return $v1;
    }

    private function round_number($n) {
        return intval(floor(floatval($n) + 0.5), 10);
    }

    private function clamp_number($n, $min, $max) {
        return min(max($n, $min), $max);
    }

    /**
     * PHP port of Javascript's "indexOf" function for strings only
     * Author: Tubal Martin http://blog.margenn.com
     *
     * @param string $haystack
     * @param string $needle
     * @param int    $offset index (optional)
     * @return int
     */
    private function index_of($haystack, $needle, $offset = 0) {
        $index = strpos($haystack, $needle, $offset);
        return ($index !== FALSE) ? $index : -1;
    }

    /**
     * PHP port of Javascript's "slice" function for strings only
     * Author: Tubal Martin http://blog.margenn.com
     * Tests: http://margenn.com/tubal/str_slice/
     *
     * @param string   $str
     * @param int      $start index
     * @param int|bool $end index (optional)
     * @return string
     */
    private function str_slice($str, $start = 0, $end = FALSE) {
        if ($end !== FALSE && ($start < 0 || $end <= 0)) {
            $max = strlen($str);
            if ($start < 0) {
                if (($start = $max + $start) < 0) {
                    return '';
                }
            }
            if ($end < 0) {
                if (($end = $max + $end) < 0) {
                    return '';
                }
            }
            if ($end <= $start) {
                return '';
            }
        }
        $slice = ($end === FALSE) ? substr($str, $start) : substr($str, $start, $end - $start);
        return ($slice === FALSE) ? '' : $slice;
    }

    /**
     * Convert strings like "64M" or "30" to int values
     * @param mixed $size
     * @return int
     */
    private function normalize_int($size) {
        if (is_string($size)) {
            switch (substr($size, -1)) {
                case 'M': case 'm': return $size * 1048576;
                case 'K': case 'k': return $size * 1024;
                case 'G': case 'g': return $size * 1073741824;
            }
        }
        return (int) $size;
    }

}
